Of that figure, only $2.7 billion paid for the 2.9 billion gallons of fuel wasted by idling vehicles.

The vast majority of the lost cash is the result of wasted time, as American workers spend their time in traffic, rather than at the office.

Congestion takes its toll of the planet as well: Most cars are at their least efficient in stop and go traffic, and the wasted fuel only makes their impact on the atmosphere worse.

Fortunately for drivers tired of spending hours in the car, national economies that could use a few extra billion dollars, and everyone hoping for a healthier planet, gridlock can be eliminated.

Approaches fall into two basic categories: Detecting traffic, and preventing it. The first camp is the domain of apps and mapping systems, which know which roads are backed up, and help drivers avoid them.

Preventing congestion without keeping people out of cars is all about making driving more efficient, by making cars and traffic control systems smarter. The technology that currently controls most traffic signals is 30-50 years behind what is now available, says Rhythm Engineering's Jenny Kutz.

More modern approaches are gradually being implemented in cities around the country and the world, and offer amazing ways to keep everyone on the road and on the move.